Powder X-ray diffraction study of ferroelectric phase transition in perovskite oxide CdTiO3
Powder X-ray diffraction study of ferroelectric phase transition in perovskite oxide CdTiO3
复制标题
钙钛矿氧化物CdTiO3铁电相变的粉末X射线衍射研究
DOI：
10.1080/00150190108008721
复制
发表时间：
2001
期刊：
影响因子：
0.8
通讯作者：
Tetsuro Nakamura
中科院分区：
文献类型：
--
作者：
Y. Shan;H. Mori;Ruiping Wang;Weiling Luan;H. Imoto;Mitsuruitoh;Tetsuro Nakamura
摘要通过介电常数、D-E环和热释电的测量，确定了钙钛矿型氧化物CdTiO 3的铁电性。铁电体的居里温度TC约为80 K，剩余极化强度为0.2 μC/cm ~ 2。低于TC时，晶格参数a的温度依赖性变为负值，而参数B和c表现出非常小的温度依赖性。在15 K下对Pnm 21、Pn 21 a和P21 ma空间群的粉末X射线衍射数据进行了Rietveld分析，它们是顺电结构空间群的非中心对称子群。由精细结构参数计算的自发极化表明CdTiO 3的铁电态可能属于Pn 21 a和P21 ma空间群。
Abstract The ferroelectricity of perovskite oxide CdTiO3 was ascertained by the measurements of the dielectric constant, D-E loops, and pyroelectricity. The ferroelectric Curie temperature TC was about 80 K and the residual electrical polarization was 0.2 μC/cm2. Below TC , the temperature dependence of the lattice parameter a turned negative while the parameters b and c showed very small temperature dependence. The Rietveld analyses of the powder X-ray diffraction date at 15 K were carried out for the space groups Pnm21, Pn21 a and P21 ma, which are noncentrosymmetric subgroups of the space group of the paraelectric structure. The spontaneous polarizations calculated from the refined structural parameters indicated that the space groups Pn21 a and P21 ma were possible for the ferroelectric state of CdTiO3.